Flotation of ores



Patented Mar. 1, 1932 UNITED STATES PATENT OFFICE 11. KEY, 01! NEW YORK, N. Y.; EDNA K. HEY SAID ADOLPHE H. NEY,DECEASED FLOTATION F ORES Ho Drawing.

This invention relates to a new and improved process for the concentration of ores by the method known as flotation and particularly to the use and employment, in said ore 5 concentration process, of chemicals and substances and transformation products thereof,

hitherto unknown as being of advantage and use as agents or assisting and auxiliary substances.in said ore concentration process as customarily practiced.

' In a pending application, Serial Number 157 ,407, I have described, and claimed, as substances which can be employed with advantage as such flotation agents, the products of reaction of an excess of disulfurdichloride upon aromatic amino compounds with at least one ortho position relative to the amino group free or unsubstituted, said products having been described in British patent specifications #17317 of 19.14 and #18,292 of 1914. In the same aforesaid pending application I have further described and claimed for the same aforesaid purpose, certain transformation products derived from said products of reaction of an excess of disulfurdichloride upon certain aromatic amino-compounds, particu- 'larly such transformation roducts. which result when said'products of reaction of disulfurdichloride upon aromatic amino com pounds are subjected, simultaneously or successively, to the action of water, or water and alkali, or water, alkali and air. 7

I have now discovered that certain other 40 transformation products of the products of upon aromatic amino compounds with at least one free or unsubstituted ortho position, are also excellent and efiicient flotation agents. These transformation upon aromatic ammo compounds. ..I have the hydrochloride of para ethoxy-aminoreaction of an excess of disulfurdichloride products may, .for instance, beobtained byallowing car-1 bondisulfide to react upon the aqueous or al- 'benzothiazole, M. R177, and '1-mercapto-3-.

Application filed (February 2, 1927. Serial No. 165,493.

further discovered that these new trans for mat-ion products are substituted mercaptobenzothiazoles and are probably formed from the disulfur'dichloride plus amine reaction products in accordance with the following I have, for instance, found that the product'obtained by subjecting the product of reaction of disulfurdichloride in excess upon benzol (para-phe-netidine) to the action of alkali and water and treating the alkaline solution of the resultin transformation product with carbondisulfi e, a product is obtained which is, after separation and purification identical with 1-mercapto-5-ethoxybenzo-thiazole M. P. 198, described by I. B.

Sebrcll and C. E. Boord, Journal Am. Chem. Soc. 45 (1923) 1290. Similarly, I have found that by subjecting the, product of reaction of disulfurdichloride in excess upon the hydrochloride of ortho toluidine to a treatment analogous to that described, 1-mercapto-5-' chlor-3-methyl-benzo-thiazole, M. P. 243 a body, as far as I am aware, hitherto unknown, is obtained. (Note: In numbering the positions in the benzo-thiazol ring the method of C.' A. Decennial Index 1910-2245 is followed.)

On subjecting the two aforenamed bodies, viz. :1-mercapto-5-ethoxy-benzo-thiazole, and 1-mercapto-5-chlor-3-1nethyl-benzo-thiazole, prepared in the manner indicated algiye from the productsof reaction of disulfurdichloride upon para-phcnetidine hydrochloride and ortho-toluidine hydrochloride, res tively, to a flotation'test, they werefoun tobe most eifective in giving a high concentrate. Similar results were obtained'when 1'-mercaptomethyl-benzo-thiazole, M. P. 186, obtained by the method described by Romani, Gazz. Chim'. Ital. 52, 29, from thiourea with sulfur in case of the former and by one of the meth- M eds described bySebrell and Boord, loo. cit.

' sulfur,

from ortho-toluidine dithiocarbamate and were employed in analogous flotation tests; when using the disulfides obtained by the action of oxidizing agents upon the meme tobenzothiazoles, results equal to or but slightly inferior to those obtained with the correspondin mercaptobenzothiazoles themselves were 0 tained.

Upon subjectin the products of reaction of sulfurdiohlori e and a and B naphthylamine to the action of water, alkali and car bondisulphide, in a manner analogous to that described in above, new bodies were obi all) tained which are possessed of the character of mercapto-aryl-thiazoles and which also influence in a ver marked degree the concentration of ores y flotation.

To illustrate the use of these substances as flotation agents, the following examples are given Example 1 1200 gr. of a sulphidic copper bearing ore, containing 1.2% on. were ground to fineness of mesh with some'water, 8 gr. slaked lime and 0.15 gr. l-mercapto-5-ethoxy-benzothiazales-as obtained by treating the product of reaction of disulfurdichloride upon para-phenetidine with water and alkali, and

the resulting alkaline solution with carbonfdisulfide, and separatin thiazoleb acidulatingt Example 2 1000 gr. of the same or used in Example 1 and ground to fineness of #60 mesh were mixed with 5 gr. slaked lime and 0.125 gr. l-mercapt-o-benzothiazole,. prepared from thiourea accordin to the method given by Romani, Gazz. C im. Ital. 52, 29 and themixture transferred to a flotation test machine and operated in a similar manner as described in Example 1. The froth when dried weighed 57 gr. and contained 10.5 gr. copper; the extraction was therefore 87.5% of the copper present and a 18.6% concentrate obtained.

Similar, and at least in one instance, viz.: with l-mercapto-5-chlor-3-methylrbenzothiazole, superior results were obtained with other substituted l-mercapto-benzothiazol'es, irrespective of the manner in which they were prepared. Also, disulfides of mercapto-benzothiazoles, as well as the alkali, earth alkali and metallic salts of l-mercapta-benzo-thiazole and substituted,1-mercapto-benzo-thiazole were found to be effective flotation agents as promoters; on the other hand, no or comparatively little effect as a flotation promoter is exercised by the acetyl conipound of l-mercapto-5-chlor-3-methyl-benzothiazole.

It is consequently justified to state that the specific and superior effect of this class of bodies, 1-mercapto-benzothiazole and such homologues and derivatives, which are substituted in the benzol nucleus, is due to the atomic arrangement and their property of being capable of assuming a tautomeric form:

C-BH

and secondarily, the property of becoming, by the action of oxidizing agents converted into disulli-des,

and that all organic bodies similarly constituted are capable in a similar degree, of influencing the separation of metallic sulphides from the gangue under conditions such as are prevalent in the ore separation proc cesses called flotation as commonly practiced.

I am well aware that this class of compounds has been recognized and is known as having par excellence the property of accelerating the vulcanization of rubber. It is obvious that no relation whatsoever can be deduced from this fact with regard to the property of this class of bodies 'to be effective flotation agents.

It is understood that my invention is in no wise limited to the proportion of materials used in the examples given, nor to the nature of the subsidiary agents or the type of the ore.

Neither would I be restricted to the use of any particular method or modus of working or operation, or to any particular t e of apparatus or machinery, all of these t ings be ing capable of variation and modification accordingvto the nature of the ore treated and the result desired.

No claim is made in this application to the. new method of preparing certain substituted l-mercaptobenzothiazole from the products of reaction of v disult'urdichloride upon aromatic amines, which is to form the subject of a separate application.

Having thus described the nature of my ore, Whic ore with said invention and in what manner it may be applied, I declare that what I claim is:

1. In the process of concentratin ores and minerals by flotation, the ste w ich comprises subjecting the ore in the orm of a pulp Y to a froth flotation operation in the presence of l-mercapto-benzothiazole substituted in the benzol nucleus by two methyl groups.

2. In the process of concentrating ores and minerals by flotation, the step which cornprises subjecting the ore in the form of a pulp to a froth flotation operation in the presence of l-mercapto-benzothiazole substituted in the benzol nucleus by two methyl groups and halogen.

3. In the process of concentratin ores and minerals by flotation, the step which comprises subjecting a sulphide ore in the form of a pulp to a froth flotation zole.

4. In the process of concentrating ores and minerals by flotation, the step which comprises subjecting a sulphide ore in the form of a pulp to a froth flotation operation in the presence of 1-mercapto-3-methyl-5-eh1or benzothiazole.

5. The rocess of concentrating a complex includes agitating a pulp of the and a frothing agent to form a mineral-bearing froth relatively rich in one of the minerals and separatin the froth so obtained.

- Signed at New ork city, in the county of New York and State of New York this twentieth day of December, A. D. 1926.

- ADOLPHE H. NEY.

operation in the presence of 1-mercapto-5-chlor-benzo-thia- I 1-mercapto-5-chlor-benzo-thiazole 

